Tapered box with self-locking cover



April 1958 A. M. ROSENFIELD 3,377,017

TAPERED BOX WITH SELF-LOCKING COVER Filed July 17, 1967 2 Sheets-Sheet l INVENTOR .Z T. .17. /2 grim/r M. 90;? /e/d April 1968 A. M ROSENFIELD 3,377,017

'I'APERED BOX WITH SELF-LOCKING COVER Filed July 17, 1967 2 Sheets-Sheet t;

INVENTOR United States Patent Office 3,3 77,017 Patented Apr. 9, 1968 3,377,017 TAPERED BOX WITH SELF-LOCKING COVER Arthur M. Rosenfield, 833 Cliifside Ave., North Woodmere, N.Y. 11598 Filed July 17, 1967, Ser. No. 653,963 1 Claim. (Cl. 22943) ABSTRACT OF THE DISCLOSURE The disclosure describes a box having an open top base and detachable cover. The box and cover are both tapered in form and interfit so that the cover is mechanically locked to the base. The cover is released by pressing the adjacent sides of the base inwardly at one corner. The material of the base is weakened at the one corner to facilitate compressing the corner.

The invention relates to the art of box construction, and more particularly concerns a box having base and self-locking cover.

Heretofore in order to detachably engage a cover to a box it has been conventional to employ cord, gummed paper or other external fastening means-In some boxes tongues and flaps are struck out of the base or cover to engage in slots formed in the cover or base respectively. The present invention by contrast makes possible a closely interfitting self-locking, quickly detachable base and cover without any auxiliary fastening means and without any tongues or flaps.

According to the invention the base is formed as a section of an inverted pyramid and the matching cover is similarly shaped. One corner of the base has weakened adjacent side portions to enable these portions to be pressed inwardly. This has the effect of distorting the base by foreshortening the base diagonally to release the one corner from the cover. Attaching the cover to the base is accomplished in the same way, namely by pressing in the adjacent weakened side portions of the one corner. When the side portions at the corner are released the flexible sides of the base straighten out to effect a snug and secure grip of the base and cover.

It is therefore one object of the invention to provide a box having an interfitting, self-locking base and cover both formed as sections of an inverted pyramid.

A further object is to provide a box as described wherein the base has trapezoidal sides which are flexible, and wherein portions of the adjacent sides at one corner are weakened to facilitate pressing the corner inwardly to foreshorten the base diagonally for releasing and mounting the cover.

Another object is to provide a box as last described, wherein the one corner of the base is weakened by grooves, slits, or other deformations of the material of the base.

For further comprehension of the invention and of the objects and advantages thereof, reference will be had to the following description and accompanying drawings and to the appended claims in which the various novel features of the invention are more particularly set forth.

In the accompanying drawings forming a material part of this disclosure:

FIGURE 1 is a perspective view of a box embodying the invention.

FIG. 2 is a vertical cross sectional view taken on line 22 of FIG. 1.

FIG. 3 is an enlarged, exploded vertical sectional view taken on line 33 of FIG. 1.

FIG. 4 is a further enlarged fragmentary horizontal sectional view taken on line 44 of FIG. 1.

FIG. 5 is a bottom plan view taken on line 55 of FIG. 1.

FIG. 6 is a horizontal sectional view taken on line 6-6 of FIG. 5.

FIG. 7 is a bottom plan view of the cover taken on line 77 of FIG. 3.

FIG. 8 and FIG. 9 are enlarged fragmentary sectional views each similar to a part of FIG. 6 and each showing a different modification of the invention.

FIG. 10 is a vertical sectional view taken on line 1010 of FIG. 9.

Referring to FIGS. 1-7 first, there is shown a box 10 having-a base 12 and cover 14. The'base has a flat bottom rectangular wall 16, flat trapezoidal end walls 18, 20 of equal size and fiat, trapezoidal side walls 22, 24 of equal size. The bottom wall, side and end walls are all joined integrally together at corner fold lines 21, 23, 25. The side and end walls of the base flare'outwardly so that the box is wider and longer at the top than it is at the closed rectangular bottom. The base in effect has the shape of an inverted truncated pyramid. The walls of the base are flexible and yield elastically to pressure applied laterally thereto.

Cover 14 has a shape which is similar to that of the base. The cover has a rectangular top wall 26, trapezoidal end walls 28 and trapezoidal side walls 30 all integrally joined at corner folds 21', 23', 25. The side and end Walls of thecover are narrower or rather shorter in depth than the depth of corresponding side and end walls of the base. The cover is also shaped as a section of an inverted pyramid with closed top and open bottom. The walls of the cover are substantially rigid and so dimensioned that the internal bottom length and width L and W indicated in FIGS. 2, 3 and 5, are respectively smaller than the external length L' and width W of the open top of the cover. By this arrangement the cover will not normally be engageable on the top of the base nor can the mounted cover be removed from the base, when the base is in an unstressed and undistorted condition as shown in FIG. 3. Interior angles A and B of the base and cover may be respectively about 100 and see FIG. 3.

One corner 25a of the base where adjacent end and side walls 18, 22 are joined together has wall portions 33, 35 weakened by opposing grooves 34, 36 and 38, 40. If these portions are pressed inwardly of the base as indicated by arrows C in FIG. 4 and as instructed by legends 42 marked as shown in FIG. 1, the diagonal dimensions D and D of the base indicated in FIG. 6 will be foreshortened. As portions of walls 18 and 22 move inwardly, the regular rectangular shape of the cover in plan view will become distorted. The distance D, D between external outer opposite diagonal corners of the base will become shorter than the corresponding diagonal internal lengths E, E lengths of the bottom of the cover. Thus the cover can easily be moved from the base or mounted thereon. When the compressed corner 25a is released, the flexible side and end walls 18, 22 elastically spring back to fiat form to lock the cover on the base if the cover is mounted thereon as shown in FIGS. 1, 2, 5 and 6. It will be noted in FIG. 6 that the external length and width L, W of the top of the base is equal to the maximum internal length and width respectively of the cover so that a snug fit and self-locking grip are effected.

A handle 50 can be attached by rivets 52 or other suitable fasten attachment means to the cover. The entire closed box with contents can be lifted by grasping the handle. The cover will not come loose from the base. The base can only be loosened from the cover and vice versa by distorting the shape of the base, and this can only be done by compressing wall portions 33, 35 at corner 25a.

FIG. 8 shows part of another box 10A in which parts corresponding to those of box are identically numbered. In this box a plurality of parallel-opposing grooves 34', 36 and 38, 40 are provided in wall portions 33, 35' of the end and side walls 18', 22' at corner 25a, of the base 12'. This arrangement permits the diagonal dimensions of the base to be foreshortened more than when only a single pair of grooves are provided in each wall, for releasing or mounting cover 14. If desired either the internal or external grooves can be omitted.

FIG. 9 and FIG. 10 show part of another box 10B in which parts corresponding to those of box 10 are indentically numbered. In this box, base 12" is provided with parallel horizontal slits 53, 54 in adjacent wall portions 33", 35" at corner 25a". A thin paper or plastic layer can be applied to the outside of the end and side walls of the base 12" to cover the slits. This layer can be decoratively ornamented if desired. When weakened corner portions 33" and 35" of walls 18", 22" are pressed inwardly the cover 14 will be released inthe same manner as described in connection with box 10. Other ways of weakening portions a corner of the base can be devised to effect foreshortening of one or both diagonal dimensions of the base.

The invention as described provides a simple, safe and effective way of self-locking a cover of a box to a base in an inexpensive way. A further advantage of the invention is the tapered shape of the box which is ornamental and attractive. Still another advantage of the invention is derived from the outwardly flared shape of the interior of the base which makes packing easier and which makes it easier to remove the contents of the base, than is possible with boxes having vertical sides.

While I have illustrated and described the preferred embodiments of my invention, it is to be understood that I do not limit myself to the precise construction herein disclosed and that various changes and modifications may be made within the scope of the invention as defined in the appended claim.

I claim:

1. A box comprising a base and cover, said base having an open rectangular top, a rectangular, closed, flat bottom wall, trapezoidal, flat opposing side walls, and trapezoidal flat end walls integrally joined together at edges thereof defining corners of the base, the open top of the base being rectangular in form and larger in length and width than the length and width respectively of the bottom -wall, said cover having a closed, flat rectangular top, an open rectangular bottom, and substantially rigid, trapezoidal flat side walls and trapezoidal flat end walls, so that both the base and cover define sections of inverted pyramids, the walls of the base all being flexible and elastically yieldable to laterally directed pressure, the maximum internal length and width dimensions of the open bottom of the cover being less than the maximum external length and width dimensions respectively of the open top of the base, so that the cover can only be fitted on the base and removed therefrom by foreshortening at least one diagonal dimension of the top of thebase, means in portions of adjacent side and end walls of the base near one corner thereof weakening and portions to facilitate flexing said adjacent sides for compressing said one corner and foreshortening at least said one diagonal dimension of the base, said weakening means comprising a plurality of slits in each of said portions to weaken the same, and a thin flexible layer covering the side wall and end wall of the base and concealing said slits.

References Cited UNITED STATES PATENTS 651,070 6/1900 Enoch 220- 2,884,181 4/1959 McCormick 229-41 2,950,040 8/ 1960 Bolding 2298 X 3,077,284 2/ 1963 McLaughlin 22060 3,259,153 7/1966 Haase 220-60 FOREIGN PATENTS 44,021 4/ 1931 Denmark.

DAVID M. BOCKENEK, Primary Examiner. 

